Acoustical board



Aug. 30, 1932. w, MASON 1,875,074

AGOUSTICAL BOARD Filed Aug. 5. 1927 mm? M BY M (70AM ATTORNEYS Patented Aug. 30, 1932 UNITED STATES PATENT OFFICE WILLIAM H. MASON, OI LAUREL, MISSISSIPPI, ASSIGNOR TO MASONI'IE CORPORATION,

OF LAUREL, MISSISSIPPI, A CORPORATION OF DELAWARE ACOUSTICAL BOARD Application filed August 5, 1927. Serial No. 210,851.

My invention relates to an acoustical board for sound absorption and reduction of sound reflection.

According to the referred form of my invention, strips of brous board, preferably board of low specific gravity, as for example boards such as commonly known as insulating board, are secured together with their edges exposed at the face of the acoustical board.

These fibrous boards, commonly used for insulating board purposes are customarily made of fibre, which is formed in water, felted into sheets, and dried. By reason of 0 having found their relative ppsitions throu h flotation, the fibres in such ards tend to ie more or less parallel to the surfaces of the insulating board, so that when a board so formed is cut, as for example by sawin the out edge contains a large proportion of severed fibre ends.

These fibre end surfaces, especially if formed by rough cutting, as by sawing, for example, apparentl have a reduced capacity for reflecting soun waves and an increased capacity for absorption of sound waves as com ared with the faces of such board.

T is effect upon reflection and absorption of sound waves can be very materially increased by arranging the component strips from which the acoustical board is formed so that certain of the strips, preferably alternate strips, project beyond the intermediate strips and thus form a ribbed or corru ated sur ace on the resulting acoustical boar and present a surface which is very highly ex tended as compared with the normal surface area. The ratio of such increased surface to the normal surface area will, of course, vary with the extent of projection of the project- .ing portions of the strips beyond the general plane of the surface. With such arrangement, the sound waves striking the lateral surfaces of the projecting portions are in part reflected and in part absorbed a number of times, and this adds very greatly to the sound absorbing capacity of the board as compared with a simpler form in which the fibre end edges are arranged in the same or substantially the same plane throughout the surface of the acoustical board.

Boards in accordance with my invention have decorative as Well as acoustic utility. For example, by painting or staining the opposite sides of the projecting portions with different colors or tones, the color scheme of a Wall may be completely changed when viewed from its opposite ends, and various other decorative effects can be simply and easily obtained.

Porous insulating boards made from wood or the like li no cellulose material exploded into substantially fibrous state in accordance with my Patent No. 1,578,609, are Well adapted for use in making acoustical boards in accordance with the present invention.

In the accompanying drawing I have shown embodiments of the invention for the purpose of illustration and affording an understandin of the invention, and without imposing limitations thereon. In said draw- T ig, 1 is a perspective view of a panel of acoustical board in which alternate component strips project beyond the intermediate strips.

Fig. 2 is a face view showing a art of a wall surfaced with panels of boar such as shown in Fig. 1.

Fig. 3 is a cross-sectional view showing the acoustical board made up of strips of irregular width and containing grooves of irregular depth, and V Fig. 4 is a cross-sectional view similar to Fig. 3 in which the acoustical board has a flat surface and is made up of strips of uniform width.

Reference character 10 designates strips of insulating board comprising fibres 12 arranged in more or less parallel relation so no usin stri s of var 'n widths. a g P Y g that the ends 14 thereof are exposed to a material extent at the edges 16 of strips 10.

In making the acoustical board shown in Fig. 1 and designated generally by reference character 18, alternate wide strips 10a and narrow strips 106' of fibrous board are ce mented or otherwise secured together with their side faces in close contact and their edges exposed at the surface of the acoustical board. The strips 10a, 10?) are preferably arranged so as to present a smooth rear surface 20 adapted to make engagement with studs, or for application to finished walls and the like, and so as to present a corrugated front surface made up of alternate projecting rib portions 22 and grooves 24, the

cut edges of the strips being exposed to form the bottoms of the grooves and the tops of the ribs, with a part of the sides of the component strips interposed therebetween and extending at substantially a right angle to the general surface of the acoustical board.

The ribs and grooves may be of substantially even projection and recession as shown in Fig. 1,-in which but two widths of strips are used, or they may vary both in extent of extension of ribs and depth of grooves by Thus in 1g. 3 an extra wide extension of a wide strip is indicated at 10c and an extra deep recess produced by use of a particularly narrow strip 1005. In Fig. 4 the strips 106 are all of the same width, and are set even in the back and provide a substantially plane surface 26 made up of the edges of strips 10a and containing cut ends of constituent fibres in largenumbers.

Fig. 2 shows some of the numerous ways in which panels of the acoustical board may be arranged in the construction or facing of walls. In this particular showing, square panels 27 a, 27?) are-arranged with their ribs directed horizontally and vertically respectively and other rectangular panels 27c'are arranged in pairs to make up squares with the ribs sometimes runnin vertically and sometimes horizontally. arious regular and hit-or-miss arrangements may be made, as will be readily understood, that shown in Fi 2 being by way of example only.

hen the ribbed construction is used, a

variety of tonal effects can be secured, as, for example, on the sidewalls of a room the side faces of the component strips which are exposed laterally and can be viewed from one end of the room may be painted or tinted with one color, and'those'viewed from the other end with a difi'erent color and, if desired, the exposed edges may be of athird color, and various other decorative effects are readily available. In coloring, the porosity -is desirably retained to as great an extent as practicable, as, for example, by tinting with water stains, or the like, so as not to 4. An acoustical board made up of 'alternately wider and narrower trimming strips of porous insulating board, the latter being so arranged that the strip edges thereof form the surface of the acousticalboard.

5. An acoustical board made up of strip trimmings of porous insulating board, said strips having their edges arranged to form a substantially plane rear surface for the acoustical board, and being of irregular width and forming a substantially grooved forward surface for the acoustical board.

6. An acoustical board formed from stri s secured together at theirmeetingfaces, t e edges of the strips forming the surface of the acoustical board.

7. An acoustical board made up ofparallel strips of porous insulating board of varying widths and exposing the edges of the component strips and parts of the side faces of said component strips.

8. An acoustical board comprising a plurality of fibre board strips secured together with lateral faces in contact with each other, the ratio of thickness to width of each strip being large, and each strip presenting in the same direction a cut surface edge.

9. An acoustical board built up by securing together the lateral faces of a plurality of fibre, board strips, the ratio of thickness to width of each strip being large, and each stri presenting in the same direction a cut sur ace edge.

10. An acoustical board built up by securing together the lateral faces of a plurality of, fibre board strips, in such relation that a series of grooves and ridges are formed, the ratio of thickness to width of each strip being large, and each strip presenting in the same direction a-cut surface edge.

11. An acoustical board built up by securing together the lateral faces of a plurality i rality of porous insulating board strips secured to ther with lateral faces in contact with eac other the ratio of thickness to width of each strip bein large, and each strip pgesenting in the same rect1on a cut surface e ge.

13. An acoustical board of fibrous material comprising a pluralit of surfaces in difierent planes substanti y arallel to each other and ex ng transverse y cut fibre ends, and ex side surfaces in angular relation thereto.

In testimony. whereof, I have signed my name hereto.

' WILLIAM H. MASON. 

